A range of FACILITY_INTERNET has been reserved for IIS components. IIS components may use values between 0xc800 and 0xcbff in the "code" field of an HRESULT. Since there is no automated way to enforce this range (and protect against duplicate codes) this text file tracks code usage. Whenever a new component needs to allocate codes within the IIS range, please update this file. .MC files used to generate HRESULTs allocated from this range should be of the following format: SeverityNames=(Success=0x0, CoError=0x2 ) FacilityNames=(Internet=0xc ) Messageid=0xc??? Facility=Internet Severity=CoError SymbolicName=WHATEVER Language=English Your message goes here. . Also, ensure the .MC file is compiled with "mc -o {other_switches}". The -o switch tells MC.EXE to generate an "OLE-style" header file. Range Component Path to .MC file ~~~~~ ~~~~~~~~~ ~~~~~~~~~~~~~~~~ c800-c80f metadata.dll iis\svcs\infocomm\metadata\interfac\mdmsg.mc c810-cbff {available}